The invention relates to a direct dye composition for keratin fibres, in particular for human keratin fibres such as the hair, comprising, in a medium which is suitable for dyeing and which is free of oxidases or oxidoreductases, at least one cationic direct dye of given formula and at least one specific polyol and/or polyol ether.
Subjects of the invention are also the dyeing processes and devices using the said composition.
In the hair sector, semi-permanent or temporary dyeing, or direct dyeing, involves dyes capable of giving the hair""s natural colour a more or less pronounced change which may withstand shampooing several times. These dyes are known as direct dyes; they can be used with or without an oxidizing agent. In the presence of an oxidizing agent, the aim is to obtain a lightening coloration. The lightening coloration is carried out by applying to the hair the mixture, prepared at the time of use, of a direct dye and an oxidizing agent, and in particular makes it possible to obtain, by lightening the melanin in the hair, an advantageous effect such as a uniform colour in the case of grey hair, or to bring out the colour in the case of naturally pigmented hair.
Among the cationic direct dyes available in the field of dyeing keratin fibres, in particular human keratin fibres, compounds which are already known are those whose structure is developed in the text which follows; nevertheless, these dyes lead to colorations which have properties that are still insufficient as regards the staying power, in terms of resistance to the various attacking factors to which the hair may be subjected (light, bad weather, shampooing).
After considerable research conducted in this matter, the Applicant has now discovered that it is possible to obtain novel compositions for the direct dyeing of keratin fibres, which are capable of leading to colorations which can be particularly resistant to the various attacking factors to which the hair may be subjected, by combining at least one specific polyol and/or polyol ether with at least one cationic direct dye known in the prior art, and of formulae respectively defined below.
This discovery forms the basis of the present invention.
A first subject of the present invention is thus a composition for the direct dyeing of keratin fibres, and in particular human keratin fibres such as the hair, containing, in a medium which is suitable for dyeing, (i) at least one cationic direct dye whose structure corresponds to the following formulae, characterized in that it also contains (ii) at least one specific polyol and/or polyol ether.
(i) The cationic direct dye which can be used according to the present invention is a compound chosen from those of formulae (I), (II), (III) and (IIIxe2x80x2) below:
a) the compounds of formula (I) below: 
in which formula (I):
D is chosen from a nitrogen atom and a xe2x80x94CH group,
R1 and R2, which may be identical or different, are chosen from a hydrogen atom, C1-C4 alkyl radicals optionally having a substituent chosen from xe2x80x94CN, xe2x80x94OH, and xe2x80x94NH2 radicals, and a 4xe2x80x2-aminophenyl radical; or form, with a carbon atom of the benzene ring, a nitrogenous heterocycle, optionally oxygenated and optionally having at least one substituent chosen from C1-C4 alkyl radicals,
R3 and Rxe2x80x23, which may be identical or different, are chosen from a hydrogen atom, halogen atoms chosen from chlorine, bromine, iodine and fluorine, and cyano, C1-C4 alkoxy, C1-C4 alkyl, and acetyloxy radicals,
Xxe2x88x92 is an anion, preferably chosen from chloride, methyl sulphate, and acetate,
A is a group chosen from structures A1 to A18 below: 
in which R4 is chosen from C1-C4 alkyl radicals which can be substituted with a hydroxyl radical and R5 is chosen from C1-C4 alkoxy radicals, with the proviso that when D is xe2x80x94CH, when A is A4 or A13 and when R3 is other than an alkoxy radical, then R1 and R2 are not simultaneously a hydrogen atom;
b) the compounds of formula (II) below: 
in which formula (II):
R6 is chosen from a hydrogen atom and C1-C4 alkyl radicals,
R7 is chosen from a hydrogen atom, alkyl radicals having a substituent chosen from xe2x80x94CN and amino radicals, and a 4xe2x80x2-aminophenyl radical, or forms, with R6, a nitrogenous heterocycle optionally oxygenated and optionally having a substituent chosen from C1-C4 alkyl radicals,
R8 and R9, which may be identical or different, are chosen from a hydrogen atom, halogen atoms, such as bromine, chlorine, or fluorine, and C1-C4 alkyl, C1-C4 alkoxy, and xe2x80x94CN radicals,
Xxe2x88x92 is an anion,
B is a group chosen from structures B1 to B6 below: 
in which R10 is chosen from C1-C4 alkyl radicals, and R11 and R12, which may be identical or different, are chosen from a hydrogen atom and C1-C4 alkyl radicals;
c) the compounds of formulae (III) and (IIIxe2x80x2) below: 
in which formulae (III) and (IIIxe2x80x2):
R13 is chosen from a hydrogen atom, C1-C4 alkoxy radicals, halogen atoms, such as bromine, chlorine, iodine and fluorine, and unsubstituted and substituted amino radicals,
R14 is chosen from a hydrogen atom, and C1-C4 alkyl radicals or forms, with a carbon atom of the benzene ring, a heterocycle which is optionally oxygenated and optionally has a substituent chosen from C1-C4 alkyl radicals,
R15 is chosen from a hydrogen atom and halogen atoms, such as bromine, chlorine, iodine and fluorine,
R16 and R17, which may be identical or different, are chosen from a hydrogen atom and C1-C4 alkyl radicals,
D1 and D2, which may be identical or different, are chosen from a nitrogen atom and a xe2x80x94CH group,
m is 0 or 1,
it being understood that when R13 is an unsubstituted amino radical, then D1 and D2 are simultaneously a xe2x80x94CH group and m is 0,
Xxe2x88x92 is an anion,
E is a group chosen from structures E1 to E8 below: 
in which Rxe2x80x2 is chosen from C1-C4 alkyl radicals;
when m is 0 and when D1 is a nitrogen atom, then E can also be a group of structure E9 below: 
in which Rxe2x80x2 is chosen from C1-C4 alkyl radicals.
The cationic direct dyes of formulae (I), (II), (III) and (IIIxe2x80x2) which can be used in the dye compositions in accordance with the invention are known compounds and are described, for example, in patent applications WO 95/01772, WO 95/15144 and EP-A-0,714,954 (the disclosures of which are specifically incorporated by reference herein).
Among the cationic direct dyes of formula (I) which can be used in the dye compositions in accordance with the invention, mention may be made more particularly of the compounds corresponding to structures (I1) to (I52) below: 
Among the compounds of structures (I1) to (I52) described above, the compounds most particularly preferred are those corresponding to structures (I1), (I2), (I14) and (I31).
Among the cationic direct dyes of formula (II) which can be used in the dye compositions in accordance with the invention, mention may be made more particularly of the compounds corresponding to structures (II1) to (II9) below: 
Among the cationic direct dyes of formula (III) which can be used in the dye compositions in accordance with the invention, mention may be made more particularly of the compounds corresponding to structures (III1) to (III18) below: 
Among the specific compounds of structures (III1) to (III18) described above, the compounds most particularly preferred are those corresponding to structures (III4), (III5) and (III13).
Among the cationic direct dyes of formula (IIIxe2x80x2) which can be used in the dye compositions in accordance with the invention, mention may be made more particularly of the compounds corresponding to structures (IIIxe2x80x21) to (IIIxe2x80x23) below: 
The cationic direct dye(s) used according to the invention preferably represent(s) from 0.001 to 10% by weight approximately relative to the total weight of the dye composition, and even more preferably from 0.005 to 5% by weight approximately relative to this weight.
(ii) For the purposes of the invention, the term xe2x80x9cpolyolxe2x80x9d denotes a compound of linear, branched or cyclic, saturated or unsaturated alkyl type bearing at least two xe2x80x94OH functions on the alkyl chain, as well as the polymers (polyethers) of these polyhydroxyalkyl compounds.
The alkyl compound preferably contains from 2 to 12 carbon atoms and even more preferably from 2 to 9.
The polyols used according to the invention can be chosen in particular from C2-C9 polyols, as well as polyalkylene glycols such as, more particularly, polyethylene glycols and polypropylene glycols.
Among the C2-C9 polyols, mention may be made in particular of glycerol, propylene glycol, 1,3-propanediol, 2-butene-1,4-diol, pentane-1,5-diol, 2,2-dimethylpropane-1,3-diol, 3-methylpentane-1,5-diol, pentane-1,2-diol, 2,2,4-trimethylpentane-1,3-diol, 2-methhylpropane-1,3-diol, hexylene glycol, 1,3-butylene glycol, dipropylene glycol, diethylene glycol and triethylene glycol.
The specific polyol ethers according to the invention are chosen from C1-C8 aliphatic ethers of C3-C9 polyols and C6-C8 aromatic ethers of C2-C9 polyols.
Among the C1-C8 aliphatic ethers of C3-C9 polyols, mention may be made in particular of propylene glycol monomethyl ether, propylene glycol monoethyl ether, isopropylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether and diethylene glycol dimethyl ether.
Among the C6-C8 aromatic ethers of C2-C9 polyols, mention may be made in particular of ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, propylene glycol monophenyl ether, propylene glycol monobenzyl ether, diethylene glycol monophenyl ether and diethylene glycol monobenzyl ether.
The polyol(s) and/or the polyol ether(s) described for the purposes of the invention are present in the dye composition in accordance with the invention in proportions generally ranging from 0.1 to 40% by weight, and even more particularly from 0.5 to 20% by weight, relative to the total weight of the composition.
The medium which is suitable for dyeing (or support) generally comprises a mixture of water and at least one polyol and/or polyol ether as defined above. It can also contain one or more organic solvents other than the polyol(s) and/or polyol ether(s) used in accordance with the invention, in order to dissolve the compounds which would not be sufficiently soluble in the medium. Organic solvents which may be mentioned, for example, are C1-C4 alkanols, such as ethanol and isopropanol, as well as aromatic alcohols such as benzyl alcohol, similar products and mixtures thereof.
The said additional organic solvents can be present in proportions preferably ranging from 0.5 to 40% by weight approximately relative to the total weight of the dye composition, and even more preferably from 1 to 20% by weight approximately.
The pH of the dye composition in accordance with the invention generally ranges from 2 to 11 approximately, and preferably from 5 to 10 approximately. It can be adjusted to the desired value using acidifying or basifying agents usually used for the direct dyeing of keratin fibres.
Among the acidifying agents, mention may be made of, for example, inorganic or organic acids such as hydrochloric acid, orthophosphoric acid, sulphuric acid, carboxylic acids such as acetic acid, tartaric acid, citric acid or lactic acid, and sulphonic acids.
Among the basifying agents, mention may be made of, for example, aqueous ammonia, alkaline carbonates, alkanolamines such as mono-, di- and triethanolamines and derivatives thereof, sodium hydroxide, potassium hydroxide and the compounds of formula (IV) below: 
in which W is a propylene residue optionally having a substituent chosen from a hydroxyl group and C1-C6 alkyl radicals; R18, R19, R20 and R21, which may be identical or different, are chosen from a hydrogen atom and C1-C6 alkyl and C1-C6 hydroxylalkyl radicals.
In addition to the cationic direct dye(s) (i) defined above, the dye composition in accordance with the invention can contain one or more additional direct dyes which may be chosen, for example, from nitrobenzene dyes, anthraquinone dyes, naphthoquinone dyes, triarylmethane dyes, xanthene dyes and azo dyes which are non-cationic.
The dye composition in accordance with the invention can also contain various adjuvants conventionally used in compositions for the direct dyeing of the hair, such as antioxidants, penetrating agents, sequestering agents, fragrances, buffers, dispersing agents, surfactants, film-forming agents, ceramides, preserving agents, screening agents and opacifiers.
Needless to say, a person skilled in the art will take care to select this or these optional complementary compound(s) such that the advantageous properties intrinsically associated with the direct dye composition in accordance with the invention are not, or are not substantially, adversely affected by the addition(s) envisaged.
The direct dye composition according to the invention can be in various forms, such as in the form of liquids, shampoos, creams or gels or any other form which is suitable for dyeing keratin fibres, and in particular human hair. It can be obtained by mixing, at the time of use, a composition, which may be a in pulverulent form, containing the cationic direct dye(s) with a composition containing the specific polyol(s) and/or polyol ether(s).
When the combination of the cationic direct dye (i) and the polyol and/or polyol ether (ii) according to the invention is used in a composition intended for lightening direct dyeing, then the dye composition in accordance with the invention also contains at least one oxidizing agent other than an enzyme such as oxidases and oxidoreductases but chosen, for example, from hydrogen peroxide, urea peroxide, alkali metal bromates, persalts such as perborates and persulphates. The use of hydrogen peroxide is particularly preferred.
Another subject of the invention is a process for the direct dyeing of keratin fibres, and in particular human keratin fibres such as the hair, using the dye composition as defined above.
According to a first variant of this direct dyeing process in accordance with the invention, at least one dye composition as defined above is applied to the fibres, for a period which is sufficient to develop the desired coloration, after which the fibres are rinsed, optionally washed with shampoo, rinsed again and dried.
The time required to develop the coloration on the keratin fibres generally ranges from 3 to 60 minutes and even more precisely from 5 to 40 minutes.
According to a second variant of this direct dyeing process in accordance with the invention, at least one dye composition as defined above is applied to the fibres, for a period which is sufficient to develop the desired coloration, without final rinsing.
According to another specific embodiment of this direct dyeing process, and when the dye composition in accordance with the invention contains at least one oxidizing agent, the dyeing process includes a preliminary step which consists in separately storing, on the one hand, a composition (A) comprising, in a medium which is suitable for dyeing, at least one cationic direct dye as defined above and, on the other hand, a composition (B) containing, in a medium which is suitable for dyeing, at least one oxidizing agent, and then in mixing them together at the time of use, after which this mixture is applied to the keratin fibres, composition (A) or composition (B) containing at least one polyol and/or polyol ether as defined above.
Another subject of the invention is a multi-compartment dyeing device or xe2x80x9ckitxe2x80x9d or any other multi-compartment packaging system, a first compartment of which contains composition (A) as defined above and a second compartment of which contains composition (B) as defined above. These devices can be equipped with means for delivering the desired mixture onto the hair, such as the devices described in patent FR-2,586,913 in the name of L""Orxc3xa9al, the disclosure of which is specifically incorporated by reference herein.
The examples which follow are intended to illustrate the invention without, however, limiting its scope.